You need to add the new rounded icons to the respective roundIcon option on the AndroidManifest. These royalty-free high-quality Android Studio Vector Icons are available in SVG, PNG, EPS, ICO, ICNS, AI, or PDF and are available as individual or icon packs. After that, the icons are created on the 'mipmap-* * * *' folder design styles for web or mobile (iOS and Android) design, marketing, or developer projects.On “Background Layer' use the background provided.On 'Foreground Layer' select the provided image and resize in order to get the proper aspect for the icon.With this elements you need to follow these steps to generate the icon with the Image Asset Studio. Image icon without background, example below (foreground).

To avoid this is necessary to create an adaptive icon. On API's > 26 android implements adaptive icons, is possible that this causes issues on app icon in existing applications, just like the following example. the solution was create adaptive icons and works perfectly.

I have found myself with an issue on my android applications not been able to use adaptive icons, resulting in ugly app icons and strange shapes in different launchers, so.

Android studio icon labels